JP2011228829A - Cable unit - Google Patents

Abstract

An object of the present invention is to provide a cable unit in which an optical signal does not leak to the outside even if an optical fiber is disconnected.
A transmitting apparatus that transmits an optical signal from a light emitting element, a receiving apparatus that includes a light receiving element that converts the received optical signal into an electrical signal, and an optical signal transmitted from the transmitting apparatus to the receiving apparatus. Cable unit 100 having an optical fiber 3 and a signal line 4 for transmitting a signal between the transmission device 1 and the reception device 2, and the reception device 2 is configured such that when the strength of the electrical signal is lower than a threshold value, The above object is achieved by the cable unit 100 characterized by stopping the transmission of the optical signal of the transmission device 1 via the signal line 4.
[Selection] Figure 1

Description

  The present invention relates to a cable unit using an optical fiber.

  Conventionally, cable units that perform optical transmission capable of high-speed communication are known. One such cable unit is a photoelectric conversion cable.

  The photoelectric conversion cable includes: a light emitting element that emits an optical signal; a light receiving element that receives the optical signal; an optical fiber that optically connects the light emitting element and the light receiving element; a power source that drives the light emitting element and the receiving element; It has a metal wire that electrically connects the element and the receiving element to the power source, and can transmit a broadband signal with low loss.

  In such a cable unit, when a detachable relay connector is provided in the middle of the cable, there is a possibility that laser light (optical signal) leaks to the outside if the relay connector is carelessly removed. Although the intensity of laser light used for data transmission is low, it is not preferable that high-intensity laser light is directly in the eyes.

  Therefore, Patent Document 1 discloses a first power supply line that can be fed from an input device (transmission device) or an output device (reception device), and the power supply line is turned back from the reception side interface to supply power to the laser light emitting element unit of the transmission side interface. An optical DVI cable (cable unit) including a second power supply line to be supplied is proposed. According to this configuration, by removing the relay connector, power supply to the laser light emitting element unit of the transmission side interface of the input device is cut off, so that laser light leaks to the outside even if the relay connector is inadvertently removed. There is nothing to do.

JP 2009-123562 A

  However, in the cable unit described in Patent Document 1, for example, when a cable composed of an optical fiber and a power supply line is bent so that only the optical fiber is disconnected and the first and second power supply lines are not disconnected, the laser light emitting element unit still remains. However, there is a possibility that the laser beam leaks to the outside by continuing to transmit the optical signal. Therefore, an object of the present invention is to provide a cable unit in which an optical signal does not leak to the outside even if an optical fiber is disconnected.

In order to achieve the above object, according to the present invention,
A transmitter for transmitting an optical signal from the light emitting element;
A receiving device having a light receiving element that converts the received optical signal into an electrical signal;
An optical fiber for transmitting the optical signal from the transmitting device to the receiving device;
A cable unit having a signal line for transmitting a signal between the transmitting device and the receiving device,
A cable unit is provided in which the receiving device stops transmission of the optical signal of the transmitting device via the signal line when the intensity of the electrical signal is lower than a threshold value.

Furthermore, according to the present invention, in the cable unit,
The signal line is preferably an insertion / extraction detection line for detecting insertion / extraction of the cable unit.
Furthermore, according to the present invention, in the cable unit,
The receiving device has a comparison unit for comparing whether the intensity of the electrical signal is lower than the threshold value,
The transmission device includes a light emitting element driving unit that drives the light emitting element,
Preferably, the signal line connects the comparison unit and the light emitting element driving unit, and the light emitting element driving unit stops driving the light emitting element according to an output of the comparison unit.
Furthermore, according to the present invention, in the cable unit,
The receiving device has a comparison unit for comparing whether the intensity of the electrical signal is lower than the threshold value,
The signal line is preferably connected to a power supply unit that drives the light emitting element and the comparison unit.
Furthermore, according to the present invention, in the cable unit,
The receiver has an amplification unit that amplifies the signal of the light receiving element,
The amplification unit preferably has a detection unit that detects the intensity of the electric signal.
Furthermore, according to the present invention, in the cable unit,
The receiver has a current mirror circuit that generates a signal that is the same as or amplified from the electrical signal,
The receiving device preferably stops the transmission of the optical signal of the transmitting device via the signal line when the intensity of the output of the current mirror circuit is lower than the threshold value.

Furthermore, according to the present invention,
A transmission device for transmitting an optical signal;
A receiving device that converts the received optical signal into an electrical signal;
A power supply unit for supplying power for driving the transmission device;
A power supply wire for electrically connecting the transmission device and the power supply unit;
A cable unit having an optical fiber for transmitting the optical signal from the transmitting device to the receiving device,
The receiving device has a comparison unit for comparing whether the intensity of the electrical signal is lower than a threshold,
The comparison unit is connected to the power supply wire,
The comparison unit is provided with a cable unit that cuts off power supply from the power supply unit to the transmission device via the power supply wire when the intensity of the electrical signal is lower than the threshold. .

Furthermore, according to the present invention, in the cable unit,
The receiver has an amplification unit that amplifies the signal of the light receiving element,
The amplification unit preferably has a detection unit that detects the intensity of the electric signal.
Furthermore, according to the present invention, in the cable unit,
The receiver has a current mirror circuit that generates a signal that is the same as or amplified from the electrical signal,
The receiving device preferably cuts off the power supply from the power supply unit to the transmitting device via the power supply wire when the output intensity of the current mirror circuit is lower than the threshold.

  According to the cable unit of the present invention, when the optical fiber is disconnected and the optical signal is not transmitted from the transmitting device to the receiving device, or when the signal strength decreases and becomes lower than the threshold value, the signal line A signal for stopping the transmission of the optical signal can be transmitted to the transmitter. Therefore, since the transmission of the optical signal of the transmission device can be stopped when the optical fiber is disconnected, it is possible to provide a highly safe cable unit that does not leak an optical signal (laser light) to the outside.

  Further, according to the cable unit of the present invention, even when there is no insertion / extraction detection line or a special signal line connecting the arithmetic processing units of the apparatus, the transmission of the optical signal is stopped by using the power supply wire. Therefore, it is possible to provide a safe cable unit in which an optical signal does not leak to the outside when the cable is disconnected.

It is a schematic diagram of the cable unit which concerns on 1st Embodiment of this invention. It is a schematic diagram of the cable unit which concerns on 2nd Embodiment of this invention. It is a schematic diagram of the cable unit which concerns on 3rd Embodiment of this invention. It is a schematic diagram of the cable unit which concerns on 4th Embodiment of this invention. It is a schematic diagram of the cable unit which concerns on the modification of 4th Embodiment of this invention. It is a schematic diagram of the cable unit which concerns on 5th Embodiment of this invention. It is a schematic diagram of the cable unit which concerns on the modification of 5th Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

<First Embodiment>
FIG. 1 is a schematic diagram of a cable unit 100 according to the first embodiment of the present invention.
The cable unit 100 according to the first embodiment includes a transmission device 1 that transmits an optical signal, a reception device 2 that converts the received optical signal into an electrical signal, and light that transmits the optical signal from the transmission device 1 to the reception device 2. It has a fiber 3 and an insertion / extraction detection line (signal line) 4 for detecting the insertion / extraction of the cable unit 100. A plurality of lines including the optical fiber 3 and the insertion / extraction detection line 4 are bundled to form one cable 5. The cable 5 may include, for example, a power supply line, a ground line, and the like in addition to the optical fiber 3 and the insertion / extraction detection line 4. The cable unit 100 connects an input device 14 that transmits an electrical signal to the transmission device 1 and an output device 15 that receives an electrical signal output from the reception device 2. In the illustrated example, only one optical fiber 3 is shown, but it goes without saying that a plurality of optical fibers 3 may be provided.

  The insertion / extraction detection line 4 is a metal wire, and a predetermined electrical signal is always applied thereto. The cable 5 is removed between the transmission device 1 and the reception device 2, or between the input device 14 and the output device 15. Thus, when the electrical signal changes, such as when the cable unit 100 is removed, the insertion / extraction of the cable 5 or the cable unit 100 can be detected. For example, when the cable 5 is not correctly attached between the transmission device 1 and the reception device 2, the cable 5 is not attached (disconnected) by detecting that a predetermined electrical signal does not flow through the insertion / extraction detection wire 4. Can be detected, and transmission of the optical signal of the light emitting device 1 can be stopped to prevent the optical signal (laser light) from leaking when the cable 5 is not attached.

  The transmission device 1 includes a light emitting element 6 that emits an optical signal according to an electrical signal, and a light emitting element driving unit 7 that drives the light emitting element 6. An electric signal is input from the input device 14 to the light emitting element driving unit 7, and the light emitting element 6 is driven according to the input electric signal. As the light emitting element 6, a VCSEL (Vertical Cavity Surface Emitting Laser) which is a kind of semiconductor light emitting laser can be used. The light emitting element driving unit 7 is driven by driving power supplied from the power supply unit 8 provided in the input device 14.

  The receiving device 2 includes a light receiving element 9 that outputs a current signal according to the light intensity of the optical signal transmitted from the light emitting element 6 through the optical fiber 3, and converts the current signal of the light receiving element 9 into a voltage signal and amplifies the signal. And an amplification unit 10 that outputs to the output device 15. As the light receiving element 9, a photodiode can be used. A transimpedance amplifier can be used as the amplification unit 10.

  The amplification unit 10 includes an amplifier 11 that converts and amplifies the current signal from the light receiving element 9 into a voltage signal, and a detection unit 12 that detects the intensity of the voltage signal amplified by the amplifier 11. The detection unit 12 outputs the intensity of the voltage signal from the amplifier 11 to the comparison circuit (comparison unit) 13.

  The comparison circuit 13 compares the intensity of the voltage signal from the amplifier 11 detected by the detection unit 12 with a threshold value, and outputs a normal value if the intensity of the current signal is equal to or greater than the threshold value, and outputs an abnormal value if the intensity is lower than the threshold value. The output of the comparison circuit 13 is transmitted to the light emitting element driving unit 7 through the insertion / extraction detection line 4. Specifically, when the optical fiber 3 is disconnected and the receiving element 8 does not receive a sufficiently strong optical signal, the voltage signal intensity becomes lower than the threshold value, and the comparison circuit 13 outputs an abnormal value. When the normal value is input to the light emitting element driving unit 7 from the comparison circuit 13, the light emitting element driving unit 7 continues to drive the light emitting element 6, but when the abnormal value is input to the light emitting element driving unit 7, the light emitting element The drive unit 7 stops driving the light emitting element 6.

  According to the cable unit 100 described above, when the optical fiber 3 is disconnected, the optical signal of the light emitting element 6 is not transmitted to the light receiving element 9, so that the intensity of the optical signal received by the light receiving element 9 is reduced. When the intensity of the received optical signal decreases, the intensity of the current signal output from the light receiving element 9 also decreases, and the intensity of the voltage signal output from the amplifier 11 also decreases. When the comparison circuit 13 determines that the intensity of the voltage signal is lower than the threshold value, the light emitting element driving unit 7 stops the operation of the light emitting element 6 through the insertion / extraction detection line 4. Therefore, since no optical signal is emitted when the optical fiber 3 is disconnected, it is possible to prevent the laser light from leaking outside.

  In the above description, the detection unit 12 has been configured to detect the voltage signal output from the amplifier 11. However, the detection unit 12 detects the current signal that is the output of the light receiving element 9, and the comparison circuit 13 outputs the voltage signal. You may compare with a threshold value.

Second Embodiment
FIG. 2 is a schematic view of a cable unit 200 according to the second embodiment of the present invention. The cable unit 200 according to the second embodiment is a modification of the first embodiment in the case where the amplification unit does not have a detection unit. In addition, the same code | symbol is attached | subjected to the member similar to 1st Embodiment, and the description is abbreviate | omitted.

  The receiving device 2a according to the present embodiment includes a light receiving element 9, an amplifier 11a that converts and amplifies a current signal output from the light receiving element 9, and a current signal output from the light receiving element 9. A current mirror circuit 16 that outputs the amplified signal and a comparison circuit 13 that compares the intensity of the current signal output from the current mirror circuit 16 with a threshold value are included.

  As in the first embodiment described above, when the intensity of the current signal from the current mirror circuit 16 is lower than the threshold value, the comparison circuit 13 sends an abnormal value to the light emitting element driving unit 7 of the transmission device 1b via the insertion / extraction detection line 4. , And the driving of the light emitting element 6 is stopped by the light emitting element driving unit 7.

  As described above, even in the cable unit 200 in the second embodiment in which the amplification unit does not have the detection unit, the driving of the light emitting element 6 is stopped when the optical fiber 3 is disconnected, and the optical signal (laser light) is leaked to the outside. Can be prevented.

<Third Embodiment>
FIG. 3 is a schematic view of a cable unit 300 according to the third embodiment of the present invention. A cable unit 300 according to the third embodiment is a modification of the first embodiment, and is provided with a central processing element 20 in the receiving device 2b, and drives the light emitting element 6 in addition to the optical fiber 3 and the insertion / extraction detection line 4. The difference from the first embodiment is that a control signal line 17b for transmitting a stop signal is provided. In addition, the same code | symbol is attached | subjected to the member similar to 1st Embodiment, and the description is abbreviate | omitted.

  The receiving device 2b in the present embodiment includes a light receiving element 9, an amplification unit 10 having an amplifier 11 and a detection unit 12, and a central processing element 20 having a comparison unit 13b that compares the intensity of the output from the detection unit 12 with a threshold value. Have The comparison unit 13b of the central processing element 20 is connected to the light emitting element driving unit 7 via the control signal line 17b. The cable 5b bundles a plurality of lines including the optical fiber 3, the insertion / extraction detection line 4, and the control signal line 17b.

  Here, the comparison unit 13b is realized as one of the functions of a central processing unit (CPU) that controls the operation of the reception device 2b. Since the transimpedance amplifier used as the amplifying unit 10 may be used in combination with a central processing element that controls the transimpedance amplifier, the function of the comparison unit 13b is added to the central processing unit 20 by incorporating the function as the comparison unit 13b. It is not necessary to provide a circuit for realizing the above as hardware in the receiving device 2b, and the cable unit 300 can be provided at low cost.

  As described above, in the cable unit 300 according to the third embodiment, as in the above-described embodiment, when the intensity of the electric signal from the detection unit 12 is lower than the threshold value, the comparison unit 13b outputs an abnormal value via the control signal line 17b. Is transmitted to the light emitting element driving unit 7, and the driving of the light emitting element 6 is stopped. Therefore, the driving of the light emitting element 6 can be stopped when the optical fiber 3 is disconnected, and leakage of the laser light to the outside can be prevented. Note that, in this embodiment, even when the insertion / extraction detection line 4 does not exist, the drive of the light emitting element 6 is stopped when the optical fiber 3 is disconnected to prevent leakage of laser light to the outside, as in the above-described embodiment. it can.

<Fourth embodiment>
FIG. 4 is a schematic view of a cable unit 400 according to the fourth embodiment of the present invention. The fourth embodiment is a modification of the third embodiment, and is different in that the comparison unit 13c is connected to the light emitting element driving unit 7 via the power control line 17c and the power supply unit 8c. In addition, the same code | symbol is attached | subjected to the member similar to 3rd Embodiment, and the description is abbreviate | omitted.

  In the cable unit 400 according to the fourth embodiment, the power supply unit 8c on the transmission device 1c side and the comparison unit 13c on the reception device 2c side are connected via the power supply control line 17c. The cable 5c bundles a plurality of lines including the optical fiber 3, the insertion / extraction detection line 4, and the power supply control line 17c.

  As in the third embodiment, the comparison unit 13c realized as one of the functions of the central processing element 20 has a normal value when the intensity of the electric signal from the detection unit 12 is equal to or greater than a threshold value, and the intensity of the electric signal. When it is lower than the threshold, an abnormal value is output. When the power supply unit 8c receives an abnormal value from the comparison unit 13 via the power supply control line 17c, the power supply unit 8c cuts off the power supply to the light emitting element driving unit 7 and stops the transmission of the optical signal of the light emitting element 6.

  As described above, the cable unit 400 according to the fourth embodiment can also stop driving the light emitting element 6 when the optical fiber 3 is disconnected, and prevent leakage of the optical signal (laser light) to the outside. Note that, in this embodiment, even when the insertion / extraction detection line 4 does not exist, the drive of the light emitting element 6 is stopped when the optical fiber 3 is disconnected to prevent leakage of laser light to the outside, as in the above-described embodiment. it can.

  In the cable unit 400 according to the above-described fourth embodiment, the comparison unit 13c is realized as one of the functions of the central processing element 20, but the cable unit according to the modification of the fourth embodiment shown in FIG. As in 400A, the comparison circuit 13 described in the first and second embodiments may be connected to the light emitting element driving unit 7 via the power control line 17c and the power unit 8c.

  The comparison circuit 13 outputs a normal value when the intensity of the electric signal from the detection unit 12 is equal to or greater than the threshold value, and outputs an abnormal value when the intensity of the electric signal is lower than the threshold value. When the power supply unit 8c receives an abnormal value from the comparison unit 13 via the power supply control line 17c, the power supply unit 8c cuts off the power supply to the light emitting element driving unit 7 and stops the transmission of the optical signal of the light emitting element 6.

  As described above, the cable unit 400 </ b> A according to the modification of the fourth embodiment can also stop driving the light emitting element 6 when the optical fiber 3 is disconnected to prevent leakage of the optical signal (laser light) to the outside. it can.

<Fifth Embodiment>
FIG. 6 is a schematic view of a cable unit 500 according to the fifth embodiment of the present invention. A cable unit 500 according to the fifth embodiment is a modification of the first embodiment. A power supply unit 8d that supplies driving power to the light emitting element driving unit 7 of the transmission device 1d without using the insertion / extraction detection line 4 is provided as an output device 15d. Is different. In addition, the same code | symbol is attached | subjected to the member similar to 1st Embodiment, and the description is abbreviate | omitted.

  In the cable unit 500 according to the fifth embodiment, the power supply unit 8d provided in the output device 15d and the light emitting element driving unit 7 provided in the transmission device 1d are connected by the power supply wire 18, and the comparison circuit 13 is connected to the power supply wire. 18 is connected. Note that the cable 5 d bundles the optical fiber 3 and the power supply wire 18.

  Since the power supply unit 8d provided in the output device 15d is connected to the light emitting element drive unit 7 of the transmission device 1d via the power supply wire 18, driving power is supplied to the light emitting element drive unit 7 when the cable 5d is not attached. Not. Therefore, even if the insertion / extraction detection line 4 is not used, the laser beam does not leak to the outside when the cable 5d is not attached.

  Further, when the comparison unit 13 outputs an abnormal value when the intensity of the electrical signal from the detection unit 12 is lower than the threshold, such as when the optical fiber 3 is disconnected, the power supply unit 8d stops supplying power to the light emitting element driving unit 7. To do. Therefore, when the optical fiber 3 is disconnected, the light emitting operation of the light emitting element 6 is stopped and the optical signal (laser light) does not leak to the outside.

  In the illustrated example, the power supply unit 8d is provided in the output device 15d, but the power supply unit may not be provided in the output device 15d and may be another external power supply. Also in this case, when the comparison circuit 13 has an abnormal value, the power supply from the external power source to the light emitting element driving unit 7 can be stopped.

  As shown in FIG. 7, when the amplification unit 10 does not have the detection unit 12, a current that generates a signal amplified the same or several times as the current signal of the light receiving element 9 as in the second embodiment. The mirror unit 16e may be provided, and the cable unit 600 may be configured so that the output of the current mirror circuit 16e is compared with the threshold value by the comparison circuit 13.

  Even in such a configuration, the comparison circuit 13 outputs an abnormal value when the intensity of the electric signal from the current mirror circuit 16e is lower than the threshold, such as when the optical fiber 3 is disconnected, and the light emitting element driving unit by the power supply unit 8e. The power supply to 7 is stopped. Therefore, when the optical fiber 3 is disconnected, the light emitting operation of the light emitting element 6 is stopped and the optical signal (laser light) does not leak to the outside.

  While the invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.

100, 200, 300, 400, 400A, 500, 600 Cable unit 1, 1b, 1c, 1d, 1e Transmitter 2, 2a, 2b, 2c, 2d, 2e Receiver 3 Optical fiber 4 Insertion / extraction detection line 6 Light emitting element 8 , 8c, 8d, 8e Power supply unit 9 Light receiving element 16, 16e Current mirror circuit 17b, 17c Signal line 18 Power supply wire

Claims (9)

A transmitter for transmitting an optical signal from the light emitting element;
A receiving device having a light receiving element that converts the received optical signal into an electrical signal;
An optical fiber for transmitting the optical signal from the transmitting device to the receiving device;
A cable unit having a signal line for transmitting a signal between the transmitting device and the receiving device,
The cable unit, wherein the receiving device stops the transmission of the optical signal of the transmitting device via the signal line when the intensity of the electric signal is lower than a threshold value.   The cable unit according to claim 1, wherein the signal line is an insertion / extraction detection line for detecting insertion / extraction of the cable unit. The receiving device has a comparison unit for comparing whether the intensity of the electrical signal is lower than the threshold value,
The transmission device includes a light emitting element driving unit that drives the light emitting element,
2. The signal line connects the comparison unit and the light emitting element driving unit, and the light emitting element driving unit stops driving the light emitting element according to an output of the comparison unit. Cable unit. The receiving device has a comparison unit for comparing whether the intensity of the electrical signal is lower than the threshold value,
The cable unit according to claim 1, wherein the signal line is connected to a power supply unit that drives the light emitting element and the comparison unit. The receiver has an amplification unit that amplifies the signal of the light receiving element,
The cable unit according to any one of claims 1 to 3, wherein the amplification unit includes a detection unit that detects the intensity of the electrical signal. The receiver has a current mirror circuit that generates a signal that is the same as or amplified from the electrical signal,
The said receiving apparatus stops transmission of the said optical signal of the said transmitting apparatus via the said signal line, when the intensity | strength of the output of the said current mirror circuit is lower than the said threshold value. The cable unit according to any one of the above. A transmission device for transmitting an optical signal;
A receiving device that converts the received optical signal into an electrical signal;
A power supply unit for supplying power for driving the transmission device;
A power supply wire for electrically connecting the transmission device and the power supply unit;
A cable unit having an optical fiber for transmitting the optical signal from the transmitting device to the receiving device,
The receiving device has a comparison unit for comparing whether the intensity of the electrical signal is lower than a threshold,
The comparison unit is connected to the power supply wire,
The said comparison part cuts off the electric power supply from the said power supply unit to the said transmitter via the said electric wire when the intensity | strength of the said electric signal is lower than the said threshold value, The cable unit characterized by the above-mentioned. The receiver has an amplification unit that amplifies the signal of the light receiving element,
The cable unit according to claim 7, wherein the amplification unit includes a detection unit that detects the intensity of the electrical signal. The receiver has a current mirror circuit that generates a signal that is the same as or amplified from the electrical signal,
The said receiving apparatus interrupts | blocks the electric power supply from the said power supply unit to the said transmitter via the said electric wire for electric power when the intensity | strength of the output of the said current mirror circuit is lower than the said threshold value. The cable unit described.

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